Proposed dioxin cleanup guidelines spark discussion in Saginaw Bay area

By Jeff Kart | The Bay City Times

December 31, 2009, 2:08PM

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A barge is in place on the Saginaw River just north of the old Wickes Park boat launch in preparation to the start of cleanup of a dioxin hot spot in 2007.

 

 

 

 

 

Public comment is being sought on more stringent guidelines for the cleanup of dioxins in soil.

The U.S. Environmental Protection Agency announced the proposed guidelines today, saying they would strengthen the agency's preliminary remediation goals at dioxin contaminated sites. The EPA is working with Midland's Dow Chemical Co. on a comprehensive cleanup of dioxin pollution in the Tittabawassee and Saginaw rivers and Saginaw Bay.

Currently, EPA’s recommended dioxin "preliminary remediation goals" are 1,000 parts per trillion for dioxin in residential soil and a level within the range of 5,000-20,000 ppt in commercial-industrial soil.

The goals announced today are lower, at 72 ppt for residential land uses and 950 ppt for commercial-industrial land uses.

Steve Chester, director of the Michigan Department of Environmental Quality, said the EPA announcement is welcome news.

"EPA's action today is a complete vindication of the DEQ staff and validation of their efforts to address the dioxin contamination existing in the city of Midland and in the Tittabawassee and Saginaw River systems," Chester said.

"The proposed dioxin cleanup standard of 72 ppt is based on the best existing science and is essentially equivalent to the state cleanup standard of 90 ppt."

The Lone Tree Council, a Saginaw Bay environmental group, also applauded the proposal.

“We knew if the science and not the politics was properly evaluated, the EPA would come back lower than Michigan’s 90 ppt for dioxin in residential soils," said spokeswoman Michelle Hurd Riddick. "The EPA numbers are far more protective of human health."

Mary Draves, a Dow spokeswoman, the guidelines don't affect a current settlement between the EPA and Dow because that agreement focuses on investigation and design of remedies.

"We believe current soil cleanup guidelines are protective of human health," Draves said. "There is a considerable body of scientific evidence ... that shows this and continues to show it."

She said the company is still reviewing the proposal.

The EPA proposal also includes consideration of the potential absorption of dioxin through skin exposure, a site evaluation that was not available when EPA last recommended preliminary remediation goals for dioxins in soil in 1998, EPA officials said in a news release.

Dioxins may cause a large number of different health effects, like cancer and reproductive effects, EPA officials say. Dioxins are of concern because they are the result of combustion, and are absorbed from the air into the food chain where they can stay for many years.

EPA will be taking public comment on the goals for 50 days following publication in the Federal Register, and anticipates issuing the final interim goals in June 2010.